Parent resolution of diagnosis and intervention fidelity in a parent-delivered intervention for pre-school children with autism: A mixed methods study

•The study 1. examined the association between parent resolution of a diagnosis in their child and their fidelity of parent delivered intervention•The study 2. described the response to their child’s diagnosis of parents considered to be resolved and unresolved•No differences in fidelity were found between parents classified as resolved and unresolved.•Parents classified as resolved reported significantly lower depression scores and lower parenting stress scores.•Child progress and parents’ hope for the future distinguished resolved and unresolved parents.•Parent wellbeing and resolution status should be assessed at entry to parent delivered intervention to provide targeted support to them.